Season the squabs with the salt and pepper.
Heat the oil in a deep skillet; saute the squabs and garlic until squabs brown.
Cover and cook over low heat 20 minutes.
Mix together the cornstarch, sugar, water, vinegar, soy sauce, and coriander.
Add to the squabs, stirring steadily until thickened.
Add the onions, tomatoes, green peppers, and cucumbers.
Cover and cook 7 minutes.